Method and apparatus for making weftless fabric



M. CASTRICUM 4 METHOD AND APPARATUS FOR MAKING WEFTLESS FABRIC Jan. 31, 1928.

Fild April 2a. 1926 RNEY.

Tss PATENT OFFICE.

MARTIN CASTBICUM, OI SPRINGFIELD, MASSACHUSETTS, ASSIGNOIB; TO THE FIB:

RUBBER COMPANY, OF CHICOPEE FALLS, MASSACHUSETTS,

MASSACHUSETTS.

A CORPORATION METHOD AND APPARATUS FOR MAKING WEFTLESS FABRIC.

Application fled April 28, 1926. .Serial No. 104,520.

For certain purposes in the arts, particularly in the building of some types of neumatic tires, it is desirable to use a ru berized fabric which has a slight extensibility produced with little or no stretching of the cords themselves. The type of rubberlzed fabric which has been customarily used for many years in the building of cord tires is composed of a warp of parallel cords hav ng widely spaced filler threads interwoven with them and covered on both sides by layers of rubber. This type of material is generally known as light weft cord fabric. More recently there has come into commercial use what is known as fillerless. fabric, which strictly is not a true fabric but a ser1es of parallel cords embedded in a matrix web of rubber. Customarily this fabric is formed by leading a series of parallel cords in accurate alignment against a sheet of rubber on a calender and pressing a second sheet of rubber upon the opposite side of the series of cords.

In the light weft type of cord fabric the cords possess what is customarily called a crimp or a slight waviness along thelr length due to the slight distorting tendency of the filler threads. These threads, although rather small in diameter, produce waves in the cords of a noticeable amount spaced apart a distance equal to the spacing of the filler threads, a distance of generally one-fourth to one-half inch. This slight waviness is taken out when the fabric is put under tension and gives a reserve of extensibility which does not require actual stretching of the cords to realize. Cord fabric of the fillerless type, on the contrary, has its cords lying straight and no extension of the fabric can occur unless the cords themselves are stretched.

It is the object of my invention to produce a weftless cord fabric having a reserve extensibility similar to that possessed by fabric of the light weft type, and to achieve this result without any time-consuming additional operations.

Referring to the drawings,

Fig. 1 is a diagrammatic cross-sectional view of a rubber sheeting calender fitted for the production of weftless cord fabric according to my invention;

Fig. 2 is a a larger scale;

fragmentary sectional view on Fig. 3', is a detail longitudinal section showing the cords attached to the first sheet of rubber; and

Fig. 4 is a similar view showing the completed rubberized fabric.

The calender shown in Fig. 1 is of the on type having rolls 10, 11, 12 and 13.mounted in a suitable frame 14. Banks of rubber 15 and 16 are placed between the two pairs of rolls to produce rubber sheets 17 and 18 respectively. A series of parallel cords 19 are 6 fed from any suitable source of supply, such as a creel 20, through a guide-board 21 and through a spacing comb 22 around roll 23 to the calender roll-12. A bar 24, having grooves corresponding to the spacing de- 71 sired for the cords, may be interposed between the roll 23 and the roll 12. As the cords meet the rubber sheet 18 they are forced into it by being pressed between roll 12 and a smaller roll 25.

According to my present invention the roll 25 is constructed with an undulating surface, as shown at 26 in Fig. 2. The pressure exerted between this roll and roll 12 will therefore vary periodically and the cords 30 will be forced into the rubber sheet 18 so that they lie in undulating paths, as clearly shown in Fig. 3. This same condition will be preserved when the compound sheet thus produced meets the rubber sheet 17, the final product being illustrated in section in Fig. 4.

It will be seen that the cord fabric produced according to my invention will have the cords lying in undulating paths simulating the crimp possessed by cord fabric of the light weft type. In fact, the cords in the fabric constructed by the process herein disclosed will be even more free than the fabric of the light weft type, since there is i no restraint due to the presence of filler threads.

Having thus described my invention, I claim:

1. A method of preparing weftless cord fabric which comprises forcing the cords into the rubber matrix by a varying pressure whereby the cords are given an undulating form.

2. A method of preparing weftless cord fabric having extensibility in excess of normal which comprises forcing the cords with a varying pressure against a matrix of sheet rubber, whereby the cords are embedded in 15 a sheet of unconnected pnralle a sheet of rubber with a rapidly varying pressure, whereby the cords are caused to assume a sinuous form, and covering the cords with a second sheet of rubber.

5. A machine for preparing weftless cord fabric having extensibility in excess of normal which comprises a roll for supporting a sheet of rubber, means for presenting a series of parallel cords to the rubber, and a roll having an undulating surface mounted adjacent the first roll and adapted to press the cords in undulating paths into the rubber surface.

MARTIN CASTRICUM. 

